The disclosed embodiments relate generally to an improvement for a xerographic fusing system and, more particularly, to a fuser cleaning system in which the error associated with detecting a web related event (such as a web low event) is minimized.
One type of electrostatographic reproducing machine is a xerographic copier or printer. In a typical xerographic copier or printer, a photoreceptor surface, for example that of a drum, is generally arranged to move in an endless path through the various processing stations of the xerographic process. As in most xerographic machines, a light image of an original document is projected or scanned onto a uniformly charged surface of a photoreceptor to form an electrostatic latent image thereon. Thereafter, the latent image is developed with an oppositely charged powdered developing material called toner to form a toner image corresponding to the latent image on the photoreceptor surface. When the photoreceptor surface is reusable, the toner image is then electrostatically transferred to a recording medium, such as paper, and the surface of the photoreceptor is cleaned and prepared to be used once again for the reproduction of a copy of an original. The paper with the powdered toner thereon in image-wise configuration is separated from the photoreceptor and moved through a fuser apparatus to permanently fix or fuse the toner image to the paper.
Typically, a fuser apparatus of the type referred to immediately above may provide a combination of heat and pressure to fix the toner image on the paper. The basic architecture of a fuser apparatus is well known. One commonly available fusing system comprises a pressure roll in contact with a rotatable heated fuser roll to form a nip between the pressure roll and the fuser roll. A sheet of paper carrying an unfused or powder toner image is passed through the nip. The side of the paper having the unfused or powder toner image typically faces the fuser roll, which is often supplied with a heat source, such as a resistance heater at the core of the fuser roll. The combination of heat from the fuser roll and pressure between the fuser roll and the pressure roll fuses the toner image to the paper, and once the fused toner cools, the image is permanently fixed to the paper.
In several known fusing systems there is provided a system by which the fuser roll can be automatically cleaned and/or supplied with a lubricant or release agent. For example, U.S. Pat. No. 6,876,832 to Pirwitz et al. discloses a fuser for an electrophotographic printer or copier with a fuser roll and pressure roll that form a nip through which a recording paper having a toner image is passed to fuse the toner image thereon. The fuser includes a cleaning web system to clean the fuser roll having a web supply roll, a tension roll to press the web against the fuser roll, and a web take up roll.
Keeping track of web usage or take up is a challenge due to the need for constant linear speed with an ever changing take up spool diameter. Tracking some aspect of an associated motor (such as counting motor steps), or mechanically sensing an amount of remaining web from supply spool diameter have each been used to gage web usage. For instance, in U.S. Pat. No. 5,049,944 to Debolt et al., the pertinent portions of which are incorporated herein by reference, a controller is used to monitor the depletion of a web by keeping track of the time the motor is running and a machine operator is advised, via an appropriate code on a display panel, when the supply of impregnated web material on the supply roll is becoming exhausted.
It is understood that various web-tracking approaches can be subject to error due to such factors as web media stretch, web material thickness variation or mechanical tolerance (between a mechanical sensing device and the supply roll). To allow for these errors, the web low event may be moved well ahead of the web out event to prevent cases where the web is completely consumed and tears off of the supply roll. As a result of moving the web low event ahead, however, extra material may be left on the spool at time of replacement, thus raising run costs due to waste.
In accordance with one aspect of disclosed embodiments there is disclosed an improved fusing system for use with a printing apparatus. The improved fusing system including a fuser roll; a take-up roll and a source roll, each one of said take-up roll and said source roll being movable; a strip of flexible material for at least one of cleaning and oiling said fuser roll, the strip of flexible material including a first portion, a second portion and a third portion, each one of the first, second and third portions having a first side and a second side; wherein the first portion is disposed adjacent the take-up roll, the second portion is initially disposed adjacent the source roll, and the third portion, which is disposed intermediate of the first portion and the second portion, is taken up by said take-up roll as both said take-up roll and said source roll are moved, and wherein the first side of the third portion contacts a portion of the fuser roll for achieving said at least one of cleaning and oiling; a detectable mark positioned on the first side of the second portion; a sensor positioned adjacent the first side of said strip of flexible material; a controller communicating with said sensor; and wherein when a substantial amount of the third portion has been taken up by the take-up roll, said detectable mark is detected by said sensor and a signal is transmitted from said sensor to said controller for indicating that the substantial amount of the third portion has been taken up by said take-up roll.
In accordance with another aspect of the disclosed embodiment there is disclosed a fuser cleaning system for use with a printing apparatus having a fuser with the fuser including a fuser roll. The fuser cleaning system includes a container for insertion into the printing apparatus, said container, when inserted into the printing apparatus, being positioned adjacent the fuser roll; a first roll and a second roll, each one of the first and second rolls being mounted within said container and being individually movable; a strip of flexible material for at least one of cleaning and oiling the fuser roll, the strip of flexible material including a first portion, a second portion and a third portion, each one of the first, second and third portions having a first side and a second side; wherein the first portion is initially disposed adjacent said first roll, the second portion is initially disposed adjacent said second roll, and the third portion, which is disposed intermediate of said first and second portions, is taken up by said first roll as the first and second rolls are moved, and wherein the first side of the third portion contacts a portion of the fuser roll for achieving said at least one of cleaning and oiling; and a detectable mark positioned in the first side of the second portion in such a manner that when said container is inserted into the printing apparatus and a substantial amount of the third portion has been taken up by said first roll, said detectable mark is detected by a sensor and a signal is transmitted from the sensor to a controller for indicating that the substantial amount of the third portion has been taken up by the first roll.
In accordance with yet another aspect of the disclosed embodiments there is disclosed a fuser cleaning system for use with a printing apparatus having a fuser with the fuser including a fuser roll. The fuser cleaning system includes a first roll and a second roll, each one of the first and second rolls being individually movable; a strip of flexible material for at least one of cleaning and oiling the fuser roll, the strip of flexible material including a first portion, a second portion and a third portion, each one of the first, second and third portions having a first side and a second side; wherein the first portion is initially disposed adjacent said first roll, the second portion is initially disposed adjacent said second roll, and the third portion, which is disposed intermediate of the first and second portions, is taken up by said first roll as said first and second rolls are moved, and wherein the first side of the third portion contacts a portion of the fuser roll for achieving said at least one of cleaning and oiling; a first detectable mark positioned in the first side of the second portion and a second detectable mark disposed intermediate of the first detectable mark and an end of the strip of flexible material; and wherein, in a first mode, when said first detectable mark is detected by a sensor, a signal is transmitted from the sensor to a controller indicating that the substantial amount of the third portion has been taken up by said first roll, and wherein, in a second mode, when said second detectable mark is detected by the sensor, a signal is transmitted from the sensor to the controller indicating that substantially all of the third portion has been taken up by said first roll.
In accordance with another aspect of the disclosed embodiments there is disclosed a method of controlling a system for cleaning and oiling a fuser roll. The method includes: providing a strip of flexible material for at least one of cleaning and oiling the fuser roll, the strip of flexible material including a first portion, a second portion and a third portion, each one of the first, second and third portions having a first side and a second side; initially disposing the first portion adjacent a first movable roll; initially disposing the second portion adjacent a second movable roll; disposing the third portion intermediate of the first and second portions so that the third portion is taken up by the first movable roll as the first and second movable rolls are moved, wherein the first side of the third portion contacts a portion of the fuser roll for achieving said at least one of cleaning and oiling; positioning a first detectable mark in the first side of the second portion; positioning a second detectable mark in the first side of the second portion intermediate of the first detectable mark and an end of the strip of flexible material; in a first mode, detecting the first detectable mark with a sensor and transmitting a first signal from the sensor to a controller indicating that a substantial amount of the third portion has been taken up by the first movable roll; and in a second mode, detecting the second detectable mark with the sensor and transmitting a second signal from the sensor to the controller indicating that substantially all of the third portion has been taken up by the first movable roll.